William mccaine



UNITED STATES PATENT DFFICEQ WILLIAM MCCAINE, on srr. PAUL, MINNESOTA,ASSIGNOR TO HELEN 'J,

MGOAINE, or SAME PLACE.

PROCESS OF TREATING PYROXYLINE COMPOUNDS.

SPECIFICATION 'foraa part of Letters Patent No. 276,443, dated April 24,1883. Application filed September 11, 1882. (Specimens) To all whom itmay concern:

Be it known that I, WILLIAM MCCAINE, of St. Paul, in thecounty of Ramseyand State of Minnesota, have invented a new and Improved Process ofTreating Pyroxyline Uompounds; and I do hereby declare that thefollowing is a full, clear, and exact description of the same.

This invention is an improved process or method of treating compoundscontaining py-V roxyline for the purpose of removing the atmospheric aircontained in cells or spaces thereof, and also for effecting the rapidevaporation of the pyroxyline solvents.

It is well known that compounds of which pyroxyline forms an element,after being dissolved, harden by evaporation of their liquid solvents,and, as the outer portion necessarily hardens first, it shrinks upon theinner portion, thus applying a pressure which tends to close the pores,so that the expulsion of the volatile solvents from the interiorrequires a comparatively long time. In fact, as a rule, the substancerequires to be kept in a kiln or drying-room,heated to about 120Fahrenheit, for a space of ten or twelve weeks, before it becomessufificiently dry to prevent further shrinkage, or hard enough to adaptit to be manufactured into the various articles it is used for.Pyroxyline com pounds are also liable, owing to the volatile nature oftheir solvents, to contain numerous air-bubbles, or spaces filled withair, which remain therein after the substance becomes hard, and hencerender it unfit for many uses. To overcome the difficulty and remove thedefect above specified, I have conceived and successfully employed theprocess hereinafter described.

In carrying out my invention in detail I pro; cecd as follows: Thepyroxyline is dissolved in any suitable solventsnch as sulphuric etherand alcohol-to which is added a small 1 quantity of oil of cassia,gum-camphor, or such other substance as willremain in the compound andact as a latent solvent when exposed to .heat, and such pigments arealso added as V are required to give it the desired color, elasticity,and weight, the whole being mixed together, either by hand or somesuitable machinery, until the ingredients have become perfectlycommingled into a homogeneous mass. The latter is then cast in molds ofany desired pattern, and allowed to remain therein from twenty-four toforty-eight hours, when it will be sufficiently hard to admit of beingcut into strips from one-fourth to one-half inch in thickness. Thestrips are placed in a kiln or drying-chamber heated to about 120'Fahrenheit, where they are allowed to remain about twenty-four hours,when they will have become sufficiently hard for the further treatmentrequired. The said strips are placed in a mold of any desired form andheated to about I50 Fahrenheit, and while thus heated subjected to apressure of about four hundred pounds to the square inch. The materialis thus compacted into a solid mass in a semidry state, havingcomparatively few air bubbles or spaces. It is to the material in thiscondition that my process is preferably applied, although it isapplicable to the material in any form if it contains a latentsolventsuch as I haveindicated.

in the molds, as above described, are converted into fine shavings,which may be convenient-ly done by a hand-plane, or by turning in alathe, and these sh avings are rubbed through I a sieve to reduce thematerial to a finely-coniininuted state-that is to say, the material isthus reduced practically to powder and for this purpose I proposetoemploy any other suitable method or means than the one above described.When in this pulverulent state the volatile solvents may be entirelyevaporated, and hence the fine particles composing it will all hardenalike when exposed to the heat ofa drying-kiln. In fact, the finer theparticles the more perfect will be the result and product obtained bythe drying process. The powderis placed in a kiln heated to 120Fahrenheit and kept therein for about; twenty-four hours, when it willbe sufficiently hard for practical purposes. The dried powderis thenplaced in a mold of the form it is desired to produce, and the mold issubjected to a heat of about 200 Fahrenheit, and while thus heat ed apressure of about one ton to the square inch is applied to compact thepowder into a solid homogeneous mass.

I am aware that pyroxyline has been reduced to fine particles by acutting or grinding process, and in that form subjected to pressureiumolds; but saturation of the compound is first necessary, in order torender it sufficiently adhesive to form a solid homogeneous mass; andafter pressing in molds the forms thus produced require to be dried fora long time in order to evaporate such solvents to a sufficient degreeto adapt the material for use. The evaporation will, however, be greaterfrom the outer than the inside, and hence the material will be hard onthe outside, butless so interiorly, and the outer portion will shrink onthe in ner In other words a defect will remain, which is 15 impossiblein the application of my process.

What I claim is- The process of treating pyroxyline compounds whichcontain a latent solvent, the same consisting in reducing the materialto powder, 20 then thoroughly drying the latter, and subjectin g, it,when dry, to heataud pressure, substantially as described.

WILLIAM MGCAINE.

Witnesses: I

WARREN H. MEAD, HERMON W, PHILLIPS.

